Tank for chromium plating



Dec. 16, 1930. 4c. R. GLEAsoN TANK FOR CHROMIUM PLATING Original Filed June 3, 1927 Patented Dec. 16, 1930 UNITED STATES C. ROY GLEASON, F CHICAGO, ILLINOIS TANK FCR CHROMIUM PILATING Application led June 3, 1927, Seria1`.No.`196,189. Renewed March 14, 1930.

In the practice of electro-deposition of chromium it is difficult to make a tank for the electrolyte that will resist the action -of chromium plating solutions. When the tank 5 itself is attacked by the electrolyte there is deterioration in the tank as a structure and a Waste of solution, and the electrolyte may also acquire additions that will reduce its efficiency and cause the quality of the work to be lowered. Thus, for example, a wooden tank is quickly rendered useless by the actlon of the usual chromium plating solutions,

Whereas a tank of iron not only depreciates but brings about the introduction of an objectionable amount of iron compounds in the plating bath. Furthermore, the anodes, the

tank and the electrolyte often create of themselves an electrolytic cell that serves no useful purpose but Whose action is sim ly injurious and wasteful. So, also, waste ul stray currents often find their way between anode and tank and between cathode and tank.

The object of the present invention is to produce a simple, novel, rugged and comparativelyinexpensive tank for holding the electrolyte used in the process of chromium plating or electro-deposition of chromium as such, which will not be attacked by the chromium plating solutions and will therefor not deterioratenor introduce objectionable compounds into the solutions, and whichwill pre-` vent waste and destructoin from current flow in directions and along paths other than those serving a useful purpose.

lf those surfaces in a tank that are in contact with the electrolyte are made of glass,

the objections heretofore enumerated will be overcome. lt is, however, diicult to produce a glass tank that will be serviceable for commercial electro-deposition of metals on a large scale and the plating of large objects. l therefore propose to construct a tank of a material having the requisite mechnical 4strength and ruggedness, and line this tank with sheets of glass accurately fitted together. lf care is taken in the shaping of the sheets or slabs of glass reasonably tight joints may be obtained without packin or cement of any kind and, in' any event, the joints will be tight 5 enough for-all practical purposes.

If the temperature of the electrolyte, in the process of chromium deposition, is desired to be at room temperature lat the start of the process and thereafter is left to take care of itself, the uniformity and quality of the Work will not be as good as though the temperature were controlled to fit t-he needs of any particular case. Afurther'object of the resent invention is to produce a simple an novel means for effectively controlling the temperature of the electrolyte so as to permit the opcrator to secure and maintain, at will, any desired temperature and avoid unevenness in the temperature during the plating operation.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:

Figure 1 is a top vplan view of a tank arranged in accordance with my invention; Fig. 2 is a view of the tank partly in elevation and partly in section; Fig. 3 is a vertical section through the bottom portion of a modified form of tank; Fig. 4 is a vertical section through still another form of tank, only a fragment bein shown; and Fig. 5 indicates' diagrammatical y automatic temperature controlling means.

Referring to Figs. 1 and 2 of the drawing, lrrepresents a rectangular steel tankof any suitable size. Beneath the tank are supporting feet 2 of porcelain or other insulating material. Around the top of the tank is a flange 1a projecting outwardly therefrom. The tank is lined with a thin layer 3 of lead over which are laid sheets or plates 4, 5 and 6 of glass. rlhe glass is preferably wire glass, as indicated in Fig. 2, to prevent displacement of the fragments in case a sheet or late is broken. Furthermore, the wire shou d be uncoated and not of the zinc coated type or- 95 dinarily employed in the manufacture of wire glass. l`-']n.-assembling the structure, the end and the side-plates are fitted in, then the bottomplate 'is' loweredl into place. lf the plates are smooth, that is, have plane sur- 100 faces, then by iinishing the edges accurately, comparatively tight joints are obtained; and there will not be enough leakage of solution or of current to be harmful. If necessary,

, the joints may be cemented with any suitable edges of these strips into the plane of thetops of the strips.

he strips may be secured to the flange by fastening devices 9, if desired. The glass is held in place by means of clamping hooks 10 secured to the strips and hooked over the upper edges of the side -and end plates.

v Bus bars A, A and B, when laid across the top of the tank, are insulated from each other and from any electrically conductive part of the tank by the insulating strips, or the glass,

or both, and ma be held in place by clamps or any other suita le means.

' these -a heated fluid oristeam while the other is For the purpose of controlling the temperature of the splution, the tank may be jackf eted or one or more pipes containing a coolingmedlum or a heating medium, orboth,

may be placed in the tank. In the arrangement 'shown ythere are in the bottom of the tank two U-shaped pipes 11 and 12 provided with risers 13 and 14 extending to and above the to of the tank .nearrone end. One of -shaped ,pipes is adapted to contain adapted'to contain 'a cooling fluid. By c'ontrollin the l'owe of the fluids or steam throng -these pipes, the temperature of the bath may be controlled and, particularly, it

^ may be maintained more uniform throughout than would ordinarily be the case. The coils must be impervious to the plating solutions and may therefore be made of lead, or vof steel, glass enamelled, or coated with like materials. f

The Apipes must be insulated from each other, from the metal of the tank and from the supply pipes leading thereto. In the arrangement shown, thepipes rest on bars 15 composed of insulating material not affected by chromium solutions; the risers are held in placeby clamps 16 also composed of insulating material not a'ected by chromium solutions; and in each riser or between each riser and its supply pipe is arranged an insulating section or coupling 17.

In the arrangement shown in Fig. 3 the lead lining is omitted, at least at the bottom.

There is a cooling pipe' 2O within 4the tank, and heat is adapted to be supplied to the bath by means of a burner 21 arranged underneath the tank. In order to prevent cracking of incassa the two. The sheet or plate 22 is held in its raisedl position by means of supporting spacers 23-that are preferably made of a inaterial that is a poor conductor of heat and is not readily attacked by the electrolytes used in electro-deposition of metals.

' In another adaptation of my invention,- the'body of the tank may be made of wood. Thus in Fig. ltthere is shown a wooden tank 25 lined with leady 26 and then with glass sheets or lates 27. In this case heat regulation may e affected in the manner shown in Figs. 1 and 2.

The temperature of the bath may be coni l trolle .Y A simple means vof accomplishing this isv illustratedin Fig. 5 wherein. 30 represents either of the pipes 11 and 12 in Fi 1 or the pipe 20 in Fig. 3. i The pipe 30y is a a ted to receive hot and cold water or stream rom the pipes 31 and 32, respectivel Between these three 'pipes is a therma y-controlled valve 33 of any usual or suitable construction, whereby water of any desired temperature may be caused to flow through temperature regulating pipe 30.

While I pre er a glass lining, in some cases bakelite, or any phenol resin material, porcelain, vitreous enamel, pyrex glass or hard i 'rubber sheets may be used as a tank lining instead of glass. n

While I have illustrated and described Iwith particularity only a single preferred form of my invention, with slight modifications,"I do not desire to belimited to the exvact structural details thus illustrated and described; but intend to cover all forms and arrangements which come within the definitions of my invention constituting the appended claims.

I claim:

1. A tank for containing the electrolyte for use -in the electro-deposition of chromium, comprising a container composed of an suit-- able material and a lining of lead an then lined with glass.

2. A tank for containing the electrolyte for use in the electro-deposition of chromium, comprising a wooden container, a lead lining in the container, and a glass covering over the lead for conta'ct with the electrolyte.

In testimony whereof, I sign this specification. l

C. ROY GLEASON.

the bottom glass sheet or plate 22 througlh contact with the hot metal bottom of tank, I raise this sheet or plate above the metal bottom so as to leave a space between 

